Sea worms, also called lake worms or water-worms, were enormous worm entities inhabiting the rainy Outer Rim Territories world of Daluuj. Circa 0 ABY, a pair of these beings resided in the depths of a mud lake, causing problems for the Heroes of Yavin by pulling the Millennium Falcon into the watery abyss. Ackbar and his team discovered firsthand that blaster shots had no effect on them. It remains a mystery what actions they took against submerged vessels, though Ackbar clarified that they do not consume them. Ackbar later theorized that the worms targeted ships due to the noise from their engines, regardless of whether they were skimmer or starship engines, which disturbed them.